1. Field of the Invention
The invention concerns a method for generation of a schedule for the implementation of examinations with an x-ray apparatus, in particular an x-ray computed tomography apparatus. The invention also concerns the use of a load calculator as well as a computer for execution of a program for implementation of the method.
2. Description of the Prior Art
According to the prior art, dates for implementation of examinations using an x-ray apparatus are assigned by medical auxiliary personnel, for example using a computer-aided schedule planner. The name of the patient, the examination to be implemented as well as an anticipated occupation time of the apparatus is entered in the procedure for assignment of a date. The estimation of the occupation time encompasses an estimation of the actual examination duration and a wait time. The wait time is necessary for cooling of the x-ray tube. During the wait time, operation of the x-ray apparatus is not possible. The length of the wait time depends on a number of parameters, for example the selected examination time, the examination duration as well as the number of previously-implemented examinations, and the like. As a consequence, the occupation duration can be different for the same examination, conducted at different times. A precise estimation of the occupation duration for a given examination requires experience. Occupation durations are particularly difficult to precisely estimate for inexperienced personnel. Errors in the estimation of the occupation durations accumulate over the day and either lead to an inadequate utilization of the x-ray apparatus or to bothersome wait times for the patient.
According to the prior art, DE 198 11 041 A1 a load calculator is disclosed that is a component of the x-ray apparatus. The temperature distribution of the anode of the x-ray tube is continuously calculated. After the end of a measurement, a wait time is determined on the basis of the calculated temperature distribution, and operation of the x-ray apparatus is blocked for the duration of the wait time to prevent a thermal overload of the x-ray tube. In this known method, the wait time for the purpose of a sufficient cooling of the x-ray tube is calculated exclusively on the basis of the power consumption up to the time of the examination under consideration.